Blackwell Reference Online

Extract

Etymologically, kind and kindred are linked. Objects belonging to the same natural kind have something special in common. The chemical elements are often taken to be paradigm cases of natural kinds. Gold is defined by its atomic number; necessarily, a thing is made of gold precisely when it is composed of atoms that have atomic number 79. Atomic number is said to provide the essence of the natural kind ( see essence/accident ). There are other properties that golden objects share that are unique to them. For example, if there are finitely many such objects in the history of the world, we could enumerate them by specifying their locations l 1 , l 2 , … l n . Why is atomic number the essence of gold, rather than the property of being found at location l 1 or l 2 or … l n ? The usual reply is that the essence of a natural kind must be necessary, explanatory and purely qualitative. It is an accident that lumps of gold have the locations just mentioned; but it is supposed to be a necessary truth that golden things have atomic number 79. In addition, atomic number explains many other properties of gold things, whereas their disjunctive location explains little ( Mill, 1843 ). And finally, it should be possible to specify the essence of gold without referring to any place, time or individual; atomic number provides this qualitative specification, but location does not. A ... log in or subscribe to read full text